"At currents as low as 60 to 100 milliamperes, low-voltage (110-220 volts), 60-hertz alternating current traveling through the chest for a split second can cause life-threatening irregular heart rhythms. About 300-500 milliamperes of direct current is needed to have the same effect."

A common misconception is that larger voltages are more dangerous
than smaller ones. However, this is not quite true. The danger
to living things comes not from the potential difference, but
rather the current flowing between two points. The reason that
people may believe this can be explained by the equation V = IR.
Since V is directly proportional to I, an increase in voltage
can mean an increase in current, if resistance (R) is kept constant.

The amount of damage done by the electric shock depends not
only on the magnitude of the current, but it also on which portions
of the body that the electric current is flowing through. The
reason for this is that different parts of the body have difference
resistances, which can lead to an increase in current, evidenced
by the formula V = IR.

An interesting fact to note is that it takes less alternating
current (AC) to do the same damage as direct current (DC). AC
will cause muscles to contract, and if the current were high enough,
one would not be able to let go of whatever is causing the current
coursing through the body. The cut-off value for this is known
as the "let-go current". For women, it is typically
5 to 7 milliamperes, and for men, typically 7 to 9 milliamperes.
This is dependent on the muscle mass of the individual.

In general, current that is fatal to humans ranges from 0.06 A
to 0.07 A, depending on the person and the type of current.